Robotic devices used in manufacturing often include a hand comprising two opposed surfaces which can move toward each other so as to grasp an object. Such hands may include a sensor on one or both of the opposing surfaces to produce a signal indicating when contact has been made with the object. The signal generated is often employed to terminate the movement of the two surfaces toward one another so as to gently grasp the object without crushing it.
When such robotic devices are used to assemble various components, the robot must be able to distinguish between the various components. Quite commonly this is done by physically locating and orientating the components of each type in a different location from each of the other component types. The robot is computer controlled such that when it needs a component of a given type it goes to the area where those components are located. In certain applications, however, it is advantageous to provide the robot with a mechanism by which it can sense the shape of the object being grasped so as to distinguish between various objects of different shapes or between different orientations of the same object. The robotic hand described above which has a single sensor mounted on each opposing surface provides only an indication of when the object has been firmly grasped and not of the shape or orientation of the object.